imx233: extend partition window support to be more generic

The new code can select among several types of window (user, system, ...).
Furthermore, the type of partitions to use is selectable in config file.
Currently, two types are support: Freescale style MBR and Creative MBLK

Change-Id: I969d60a3d08f2c9448fb4b9c440051b7801b94cd

3 files changed, 145 insertions, 23 deletions

diff --git a/firmware/target/arm/imx233/partitions-imx233.c b/firmware/target/arm/imx233/partitions-imx233.c
index 06c5a48f32..ebc7b9a6e6 100644
--- a/firmware/target/arm/imx233/partitions-imx233.c
+++ b/firmware/target/arm/imx233/partitions-imx233.c
@@ -19,6 +19,7 @@
  *
  ****************************************************************************/
 #include "partitions-imx233.h"
+#include "string.h"
 
 static bool enable_window = true;
 
@@ -32,8 +33,79 @@ bool imx233_partitions_is_window_enabled(void)
     return enable_window;
 }
 
-int imx233_partitions_compute_window(uint8_t mbr[512], unsigned *start, unsigned *end)
+#if (IMX233_PARTITIONS & IMX233_CREATIVE)
+#define MBLK_MAGIC  0x4d424c4b /* MBLK */
+#define MBLK_COUNT  31
+/* MBLK is not located in the first sector !
+ * Creative code uses the hard-coded *absolute* address 0x3ffe00,
+ * bypassing all partition related information !!
+ * NOTE: for some reason, the ZEN uses a different value ?! */
+#ifdef CREATIVE_ZEN
+#define MBLK_ADDR   0x400000
+#else
+#define MBLK_ADDR   0x3ffe00
+#endif
+
+struct mblk_header_t
+{
+    uint32_t magic;
+    uint32_t block_size;
+    uint64_t total_size;
+} __attribute__((packed));
+
+struct mblk_partition_t
+{
+    uint32_t size;
+    uint32_t start;
+    char name[8];
+} __attribute__((packed));
+
+static const char *creative_part_name(enum imx233_part_t part)
+{
+    switch(part)
+    {
+        case IMX233_PART_USER: return "cfs";
+        case IMX233_PART_CFS: return "cfs";
+        case IMX233_PART_MINIFS: return "minifs";
+        default: return "";
+    }
+}
+
+static int compute_window_creative(IF_MD(int drive,) enum imx233_part_t part,
+    unsigned *start, unsigned *end)
 {
+    uint8_t mblk[512];
+    int ret = storage_read_sectors(IF_MD(drive,) MBLK_ADDR / 512, 1, mblk);
+    if(ret < 0)
+        return ret;
+    struct mblk_header_t *hdr = (void *)mblk;
+    if(hdr->magic != MBLK_MAGIC)
+        return -70; /* bad magic */
+    struct mblk_partition_t *ent = (void *)(hdr + 1);
+    const char *name = creative_part_name(part);
+    for(int i = 0; i < MBLK_COUNT; i++)
+    {
+        if(ent[i].name[0] == 0)
+            continue;
+        if(strcmp(ent[i].name, name) == 0)
+        {
+            *start = ent[i].start * hdr->block_size / 512;
+            *end = *start + ent[i].size * hdr->block_size / 512;
+            return 0;
+        }
+    }
+    return -80; /* not found */
+}
+#endif /* #(IMX233_PARTITIONS & IMX233_CREATIVE) */
+
+#if (IMX233_PARTITIONS & IMX233_FREESCALE)
+static int compute_window_freescale(IF_MD(int drive,) enum imx233_part_t part,
+    unsigned *start, unsigned *end)
+{
+    uint8_t mbr[512];
+    int ret = storage_read_sectors(IF_MD(drive,) 0, 1, mbr);
+    if(ret < 0)
+        return ret;
     /**
      * Freescale uses a strange layout: is has a first MBR at sector 0 with four entries:
      * 1) Actual user partition
@@ -54,19 +126,54 @@ int imx233_partitions_compute_window(uint8_t mbr[512], unsigned *start, unsigned
      * it seems that it is similarly truncated. */
     if(mbr[510] != 0x55 || mbr[511] != 0xAA)
         return -101; /* invalid MBR */
-    /* sanity check that the first partition is greater than 2Gib */
-    uint8_t *ent = &mbr[446];
-    *start = ent[8] | ent[9] << 8 | ent[10] << 16 | ent[11] << 24;
-    /* ignore two lowest bits(see comment above) */
-    *start &= ~3;
-    *end = (ent[12] | ent[13] << 8 | ent[14] << 16 | ent[15] << 24);
-    *end &= ~3;
-    /* ignore two lowest bits(order is important, first truncate then add start) */
-    *end += *start;
-    
-    if(ent[4] == 0x53)
-        return -102; /* sigmatel partition */
-    if((*end - *start) < 4 * 1024 * 1024)
-        return -103; /* partition too small */
-    return 0;
+    if(part == IMX233_PART_USER)
+    {
+        /* sanity check that the first partition is greater than 2Gib */
+        uint8_t *ent = &mbr[446];
+        *start = ent[8] | ent[9] << 8 | ent[10] << 16 | ent[11] << 24;
+        /* ignore two lowest bits(see comment above) */
+        *start &= ~3;
+        *end = (ent[12] | ent[13] << 8 | ent[14] << 16 | ent[15] << 24);
+        *end &= ~3;
+        /* ignore two lowest bits(order is important, first truncate then add start) */
+        *end += *start;
+
+        if(ent[4] == 0x53)
+            return -102; /* sigmatel partition */
+        if((*end - *start) < 4 * 1024 * 1024)
+            return -103; /* partition too small */
+        return 0;
+    }
+    else if(part == IMX233_PART_BOOT)
+    {
+        /* sanity check that the second partition is correct */
+        uint8_t *ent = &mbr[462];
+        if(ent[4] != 0x53)
+            return -104; /* wrong type */
+        *start = ent[8] | ent[9] << 8 | ent[10] << 16 | ent[11] << 24;
+        *end = (ent[12] | ent[13] << 8 | ent[14] << 16 | ent[15] << 24);
+        *end += *start;
+
+        return 0;
+    }
+    else
+        return -50;
+}
+#endif /* (IMX233_PARTITIONS & IMX233_FREESCALE) */
+
+int imx233_partitions_compute_window(IF_MD(int drive,) enum imx233_part_t part,
+    unsigned *start, unsigned *end)
+{
+    int ret = -1;
+#if (IMX233_PARTITIONS & IMX233_CREATIVE)
+    ret = compute_window_creative(IF_MD(drive,) part, start, end);
+    if(ret >= 0)
+        return ret;
+#endif
+#if (IMX233_PARTITIONS & IMX233_FREESCALE)
+    ret = compute_window_freescale(IF_MD(drive,) part, start, end);
+    if(ret >= 0)
+        return ret;
+#endif
+    return ret;
 }
diff --git a/firmware/target/arm/imx233/partitions-imx233.h b/firmware/target/arm/imx233/partitions-imx233.h
index 4490aad77f..b7ed251dee 100644
--- a/firmware/target/arm/imx233/partitions-imx233.h
+++ b/firmware/target/arm/imx233/partitions-imx233.h
@@ -24,10 +24,27 @@
 #include "system.h"
 #include "storage.h"
 
+#ifndef IMX233_PARTITIONS
+#error You must define IMX233_PARTITIONS
+#endif
+
+enum imx233_part_t
+{
+    IMX233_PART_USER,
+#if (IMX233_PARTITIONS & IMX233_FREESCALE)
+    IMX233_PART_BOOT,
+#endif
+#if (IMX233_PARTITIONS & IMX233_CREATIVE)
+    IMX233_PART_CFS,
+    IMX233_PART_MINIFS,
+#endif
+};
+
 /* Enable/Disable window computations for internal storage following the
  * Freescale convention */
 void imx233_partitions_enable_window(bool enable);
 bool imx233_partitions_is_window_enabled(void);
-int imx233_partitions_compute_window(uint8_t mbr[512], unsigned *start, unsigned *end);
+int imx233_partitions_compute_window(IF_MD(int drive,) enum imx233_part_t part,
+    unsigned *start, unsigned *end);
 
 #endif /* __PARTITIONS_IMX233__ */
\ No newline at end of file
diff --git a/firmware/target/arm/imx233/sdmmc-imx233.c b/firmware/target/arm/imx233/sdmmc-imx233.c
index a4329b1416..978e5b7247 100644
--- a/firmware/target/arm/imx233/sdmmc-imx233.c
+++ b/firmware/target/arm/imx233/sdmmc-imx233.c
@@ -664,12 +664,10 @@ static int init_drive(int drive)
     /* compute window */
     if((SDMMC_FLAGS(drive) & WINDOW) && imx233_partitions_is_window_enabled())
     {
-        uint8_t mbr[512];
-        int ret = transfer_sectors(drive, 0, 1, mbr, true);
-        if(ret)
-            panicf("Cannot read MBR: %d", ret);
-        ret = imx233_partitions_compute_window(mbr, &window_start[drive],
-            &window_end[drive]);
+        /* NOTE: at this point the window shows the whole disk so raw disk
+         * accesses can be made to lookup partitions */
+        ret = imx233_partitions_compute_window(IF_MD(drive,) IMX233_PART_USER,
+            &window_start[drive], &window_end[drive]);
         if(ret)
             panicf("cannot compute partitions window: %d", ret);
         SDMMC_INFO(drive).numblocks = window_end[drive] - window_start[drive];